Data in electronic circuits may be stored in memory, for example, semiconductor memory. Examples of semiconductor memory include volatile memory, which is limited to storing data while power is provided to the memory, and non-volatile memory, which can store data even when power is no longer provided to the memory. Non-volatile memories have become more popular as mobile and compact electronic devices, for example, mobile phones, digital cameras, portable computers, and other such devices, require storage of information even after the electronic device is switched off.
Memory typically includes an array of memory cells which are used to store data. The memory cells are arranged in the array in a manner which can be addressed using memory addresses. The memory addresses are provided to the memory and decoded by address decoders to select a memory location or locations corresponding to a memory address. In operating the address decoders, the memory locations corresponding to the memory address are selected while the remaining memory locations remain deselected in order to preserve the data stored by the deselected memory locations.
In decoding memory addresses, circuitry included in the address decoders are operated by biasing the various circuitry, for example, decoders switches, to different voltages. For example, voltages are provided to close decoder switches coupled to memory locations to be accessed while decoder switches coupled to deselected memory locations are biased to remain open. The voltages applied to the decoder circuitry over time may degrade their performance, and in extreme cases, cause the circuitry to fail such as due to voltage induced stresses. In these cases where the decoder circuitry fails, the memory may become non-functional.
Therefore, it is desirable to have alternative designs for decoder circuitry and alternative methods for operating decoder circuitry.